Flexible bladder for soaking the earth and collecting earthworms and method of use

Abstract

A flat and thin bladder device is used to cause earthworms to migrate to the earth's surface for easy collection. The bladder is laid flat on the earth's surface and has a maximum thickness between its top wall and bottom wall of not over about 5 centimeters but has area dimensions greater than 1 meter in all directions and not greater than about 4 meters in all directions. The maximum thickness of the bladder is limited by a pattern of spaced connections between the top wall and bottom wall forming the bladder. At least the bottom wall is opaque to block out light under it, and the bottom wall has a plurality of openings that are substantially uniformly distributed for the escape of water from the bladder to earth underlying the bottom wall. Water is introduced to the bladder at a rate about equal to the rate of water escaping from the bottom wall. Soaking the earth under the bladder causes earthworms to migrate to the surface and they are then easily collected as portions of the bladder are lifted to expose them.

That which is claimed is: 
     
       1. A device for causing earthworms to migrate to the earth's surface for easy collection, said device comprising a flexible, substantially flat and thin bladder capable of being laid in flat condition on the earth's surface and having a top wall and a bottom wall of flexible sheet material defining the top and bottom limits of the bladder interior, said bladder having a maximum interior thickness between said top wall and bottom wall of not over about 5 centimeters when said bladder is filled with water after being laid in flat condition on the surface of the earth, said bladder having area dimensions greater than about 1 meter in all directions transverse to said thickness and not greater than about 4 meters in all directions transverse to said thickness, said maximum thickness of said bladder being limited by the fact that said top wall and said bottom wall are held against greater spacing from each other than about 5 centimeters by a pattern of spaced connections therebetween, at least said bottom wall being opaque to block out light under it when it is placed adjacent the earth, there being a plurality of openings substantially uniformly distributed through said bottom wall for the escape of water from said bladder to earth underlying said bottom wall, and a water entrance conduit extending from the interior of said bladder to the exterior thereof and functioning as a conduit for supplying water to said bladder. 
     
     
       2. The device of claim 1 wherein the size and substantially uniform distribution of said openings through said bottom wall are such that at least about two gallons of water will pass through the openings of a square meter of the bottom wall per minute when the water supplied through said water entrance conduit is incoming at a rate sufficient to maintain the bladder in fully filled condition as water continually escapes through the openings of the bottom wall. 
     
     
       3. The device of claim 1 wherein said maximum thickness between said top wall and bottom wall is limited to no more than about 2 centimeters by said spaced connections therebetween. 
     
     
       4. The device of claim 1 wherein said openings of said bottom layer have a size greater than about 3 millimeters in diameter and are in a pattern such that the greatest spacing between adjacent openings is not in excess of 20 centimeters. 
     
     
       5. The device of claim 1 wherein said top and bottom walls are formed of plastic film and said openings are apertures in the plastic film of said bottom wall. 
     
     
       6. A method for collecting earthworms comprising: a) laying a substantially flat and thin bladder on an area of the earth's surface where the underlying earth contains a random distribution of earthworms, said bladder being sufficiently opaque to block out light penetration through it to the underlying earth, and said bladder having a bottom wall adjacent the earth's surface equipped with openings for the passage of water therethrough to soak the earth therebeneath,   b) continuously supplying water to said bladder for passage through the openings of the bottom wall of said bladder into the earth underlying said bottom wall so as to soak the earth underlying said bottom wall within a period of time from about 5 minutes up to about 30 minutes, to thereby stimulate earthworms in the underlying earth to migrate out of the soaked earth onto the area of the earth's surface underneath said bottom layer,   c) sequentially removing limited portions of said bladder from the earth's surface while simultaneously, as each portion of the earth's surface is exposed, collecting earthworms that have migrated to the earth's surface and lie thereupon at the time the portion of the bladder is removed therefrom, and   d) placing collected earthworms in a container as they are collected.   
     
     
       7. The method of claim 6 wherein said laying step is preceded by the step of providing said bladder with bottom wall openings of a size and substantially uniform distribution as to pass at least about two gallons of water per minute through a square meter of said bottom wall when said step of continuously supplying water to said bladder is conducted. 
     
     
       8. The method of claim 6 wherein said water is supplied to said bladder at a rate about equal to the rate at which water passes through said openings of said bottom wall. 
     
     
       9. The method of claim 6 conducted so as to maintain the height of water within said bladder below about 3 centimeters so as to minimize the weight of bladder water per unit of area of the underlying earth.